1. Field of the Invention
The present invention relates to display apparatus, and it particularly relates to a technology by which to improve the electrical characteristics and the degree of design freedom in the active matrix display apparatus.
2. Description of the Related Art
The use of notebook type personal computers and portable terminals is spreading rapidly. Displays mainly used for such equipment are liquid crystal displays, but the display considered promising as a next-generation flat display panel is the organic EL (Electro Luminescence) display. It is the active matrix drive system that is central as a display method for such displays. The display using this system is called the active matrix display where a multiplicity of pixels are vertically and horizontally disposed in a matrix, and a switching element is provided for each pixel. Image data are written sequentially for each pixel line by the switching element. A variety of designs for achieving the practical organic EL displays are being proposed. One example of such designs is disclosed in Japanese Patent Application Laid-Open No. 2002-32058 or No. 2001-109395.
An organic EL display is comprised mainly of a display region constituted by a multiplicity of pixels and a peripheral region around the display region. Disposed in the peripheral region are display control circuits, signal lines, power supply lines and so forth. In designing the organic EL display, which is now on its way for wider acceptance in the world, attempts to improve electrical characteristics and achieve smaller size for the equipment are among the most important considerations in gaining greater competitiveness for the product in the market. Those two goals may often be regarded as opposing factors in design. However, the inventors have discovered that they can be reconciled with each other and even coexist through a set of improvements in packaging design.